Gamma radiation induced cytological abnormalities in Lycopersicon esculentum Mill. var. pusa ruby.

Srivastava

2013

Summary Mutagenic effectiveness and efficiency is an important factor for the selection of a mutagen for a mutation breeding program. Mutagenic effectiveness is a measure of the frequency of mutations induced by a unit mutagen dose, while mutagenic efficiency is a measure of the proportion of mutations in relation to undesirable changes such as lethality, sterility, meiotic aberrations etc. The present study envisages the mutagenic effectiveness and efficiency of individual and combined treatments of chemical and physical mutagens i.e. sodium azide (individual), gamma rays (individual) and sodium azide+gamma ray (combined). For the individual treatment of sodium azide, the seeds of the Sesbania cannabina variety nD-1 were treated with 0.5% solution of sodium azide (Sa) for four different time durations, i.e. 3, 5, 7, and 9 h, and for the individual treatment of gamma rays, dry and healthy seeds were treated with 20, 40, 60, and 80 Kr doses of gamma rays. For the combined treatment, the seeds were exposed to four different doses of gamma rays (20, 40, 60, and 80 Kr) and after irradiation seeds were treated with 0.5% solution of sodium azide for 3 h. after treatment, seeds subjected to individual and combined treatment were sown in randomized block design to raise the M 1 generation and a study was conducted on germination percentage, survival percentage, pollen fertility percentage, and chromosomal aberrations at different doses of the individual and combined treatments.

Section: Discussionmentioning

confidence: 74%

Section: Discussionmentioning

confidence: 99%

Efficiency and Effectiveness of Gamma Rays and Sodium Azide in Sesbania cannabina Poir.

Srivastava

2013

“…Stickiness has been reported to be a result of partial dissociation of nucleoproteins and alterations in the pattern of organization of chromosomes by Evans (1962) while Jayabalan and Rao (1987) attributed it to be due to the disturbances in cytochemically balanced reactions. However, it seems most probable that the gamma rays may have caused some kind of gene mutation, which leads to incorrect coding of some non-histone proteins involved in chromosome organization.…”

Section: Discussionmentioning

confidence: 99%

Mutagenic Efficiency of Lower Doses of Gamma rays in Black Cumin (Nigella sativa L.)

Gupta

2007

SummaryThe seeds of Nigella sativa were treated with 50, 100, 150, 200, 250, 300 Gy doses of gamma rays. A hexapetalous mutant was observed at 100 Gy dose in M 1 generation. It was found to have increased seed weight and seed number as compared to the control plants. The chromosomal abnormalities at 100 Gy dose were also at the optimum level (17.10%). Therefore, this dose can be suggested to be beneficial for mutagenesis in plants.

“…Stebbins (1950) and Darlington (1928) interpreted secondary associations to be a result of modified chromosome arrangements due to duplication, interchanges or stickiness. Jayabalan and Rao (1987) reported stickiness due to disturbances in the cytochemically balanced reactions. Evans (1986) reported stickiness to be a result of partial dissociation of nucleoproteins and changes in the pattern of organization.…”

Section: Discussionmentioning

confidence: 99%

Influence of Drought Stress on Cytological Behavior of Green Manure Crop Sesbania cannabina Poir.

Srivastava

2014

Summary Among the most important environmental stresses, drought is the most significant stress affecting crop production. Effects of drought stress on the morphological parameters of plants are well studied and understood, but studies on the effect of drought stress on the chromosomal biology of plants are scarce. Therefore, the present study was conducted to study the effect of drought stress on the chromosomal biology of the drought-resistant green manure crop Sesbania cannabina. The present experimentation was conducted at the Department of Botany, University of Allahabad. Dry and healthy seeds of Sesbania cannabina variety ND-1 were soaked in distilled water and used for sowing in experimental pots to raise the population. After 15 days, seedlings were exposed to drought stress for different time durations (viz., 10, 15 and 20 days). On the onset of budding, young floral buds were fixed in carnoy s fixative and were used for cytological studies. Cytological studies clearly showed the chromotoxic behaviour of drought stress.